491 research outputs found
Erosión en bancales: la trayectora de la escorrentía y su relación con el deterioro del Ribazo (Norte Comunidad Valenciana)
[Resumen] El cultivo en terrazas requiere la adecuación del terreno a las labores agrícolas: reducción de la erosión, favorecimiento de la infiltración, y hacer más cómodas las labores agrícolas. Estos objetivos se consiguen, en su mayor parte, reduciendo la pendiente de la ladera. La solución que se dé al drenaje de la escorrentía en la explotación determina, según se comenta en este artículo, la vulnerabilidad de los muros, sobre todo cuando las labores de mantenimiento se abandonan, como es el caso en extensas áreas montañosas de la península.[Abstract] The terrace cultivation needs a suitable field for farming works: to reduce the erosion, to permit infiltration and to do more comfortable farming works. You can reach most of these aims reducing the slope. The solution for the water drainage in the fields cause, as the article says, the vulnerability of the walls, especially when the maintenance works are left, as in vast mountains areas in the peninsula
The Brasselet-Sch\"urmann-Yokura conjecture on -classes of singular varieties
We prove the Brasselet-Sch\"urmann-Yokura conjecture, which predicts the
equality between the Hodge L-class and the Goresky-MacPherson L-class for
compact complex algebraic varieties that are rational homology manifolds
Production and characterization of activated carbon from barley straw by physical activation with carbon dioxide and steam
In recent years, the growth of environmental protection policies has generated an increase in the global demand for activated carbon, the most widely used adsorbent in many industrial sectors, and with good prospects of implementation in others such as energy storage (electrodes in supercapacitors) and agriculture (fertilizer production). This demand is driving by the search for renewable, abundant and low-cost precursor materials, as an alternative to traditional fossil sources. This study investigates the production of activated carbon from barley straw using physical activation method with two different activating agents, carbon dioxide and steam. Experimental tests under different conditions at each stage of the process, carbonization and activation, have been conducted in order to maximize the BET surface area and microporosity of the final product. During the carbonization stage, temperature and heating rate have been found to be the most relevant factors, while activation temperature and hold time played this role during activation. Optimal conditions for the activation stage were obtained at 800 °C and a hold time of 1 h in the case of activation with carbon dioxide and at 700 °C and a hold time of 1 h in the case of activation with steam. The maximum BET surface area and micropore volume achieved by carbon dioxide activation were of 789 m2/g and 0.3268 cm3/g while for steam activation were 552 m2/g and 0.2304 cm3/g, which represent respectively an increase of more than 43% and 42% for the case of activation with carbon dioxide
Pooled Time Series Modeling Reveals Smoking Habit Memory Pattern
Smoking is a habit that is hard to break because nicotine is highly addictive and smoking
behavior is strongly linked to multiple daily activities and routines. Here, we explored the
effect of gender, age, day of the week, and previous smoking on the number of cigarettes
smoked on any given day. Data consisted of daily records of the number of cigarettes
participants smoked over an average period of 84 days. The sample included smokers (36
men and 26 women), aged between 18 and 26 years, who smoked at least five cigarettes
a day and had smoked for at least 2 years. A panel data analysis was performed by way of
multilevel pooled time series modeling. Smoking on any given day was a function of the
number of cigarettes smoked on the previous day, and 2, 7, 14, 21, 28, 35, 42, 49, and 56
days previously, and the day of the week. Neither gender nor age influenced this pattern,
with no multilevel effects being detected, thus the behavior of all participants fitted the
same smoking model. These novel findings show empirically that smoking behavior is
governed by firmly established temporal dependence patterns and inform temporal
parameters for the rational design of smoking cessation programs
Power quality in high-tech campus: an exemplary case study
This paper presents preliminary results from a power quality audit conducted at a high-tech campus over last year. Voltage and current were measured at various R&D buildings. The paper examines the causes and effects of power disturbances that affect computer or any other microprocessor based equipment and analyses the auto-protection capabilities of modern power supplies. The convenience of “enhanced power supply” or “low-cost customer-side” protection solutions is also discussed. Finally it is addressed the role of the Standards on the protection of electronic equipment and the implications for the final costume
Serum proteomics of active tuberculosis patients and contacts reveals unique processes activated during Mycobacterium tuberculosis infection.
Tuberculosis (TB) is the most lethal infection among infectious diseases. The specific aim of this study was to establish panels of serum protein biomarkers representative of active TB patients and their household contacts who were either infected (LTBI) or uninfected (EMI-TB Discovery Cohort, Pontevedra Region, Spain). A TMT (Tamdem mass tags) 10plex-based quantitative proteomics study was performed in quintuplicate containing a total of 15 individual serum samples per group. Peptides were analyzed in an LC-Orbitrap Elite platform, and raw data were processed using Proteome Discoverer 2.1. A total of 418 proteins were quantified. The specific protein signature of active TB patients was characterized by an accumulation of proteins related to complement activation, inflammation and modulation of immune response and also by a decrease of a small subset of proteins, including apolipoprotein A and serotransferrin, indicating the importance of lipid transport and iron assimilation in the progression of the disease. This signature was verified by the targeted measurement of selected candidates in a second cohort (EMI-TB Verification Cohort, Maputo Region, Mozambique) by ELISA and nephelometry techniques. These findings will aid our understanding of the complex metabolic processes associated with TB progression from LTBI to active disease
Uso de las terapias biológicas en las enfermedades autoinmunes sistémicas
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Feedback-related Brain Potential Activity Complies with Basic Assumptions of Associative Learning Theory
Feedback-related negativity (FRN) is an ERP component that distinguishes positive from negative feedback. FRN has been hypothesized to be the product of an error signal that may be used to adjust future behavior. In addition, associative learning models assume that the trial-to-trial learning of cueoutcome mappings involves the minimization of an error term. This study evaluated whether FRN is a possible electrophysiological correlate of this error term in a predictive learning task where human subjects were asked to learn different cueoutcome relationships. Specifically, we evaluated the sensitivity of the FRN to the course of learning when different stimuli interact or compete to become a predictor of certain outcomes. Importantly, some of these cues were blocked by more informative or predictive cues (i.e., the blocking effect). Interestingly, the present results show that both learning and blocking affect the amplitude of the FRN component. Furthermore, independent analyses of positive and negative feedback event-related signals showed that the learning effect was restricted to the ERP component elicited by positive feedback. The blocking test showed differences in the FRN magnitude between a predictive and a blocked cue. Overall, the present results show that ERPs that are related to feedback processing correspond to the main predictions of associative learning models.
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